When you run into old friends, it's not uncommon to be struck by how they've changed - not just in physiology, but in character.
You might think you haven't changed much in terms of personality since you were a child - we like to believe we hold unique, indelible character traits.
But recent research suggests this thinking is all vain cobblers.
The longest personality study of all time suggests that over the course of a lifetime, just as all your physical cells are replaced and your appearance changes, your personality undergoes a change as well.
The study, published in the journal Psychology and Ageing, began with a 1950 survey of 1,208 14-year-olds in Scotland.
Their teachers were asked to use six questionnaires to rate the teenagers on six different personality traits:
- Desire to learn
- Stability of moods
The results of all the questionnaires were combined to one trait, defined as "dependability".
Fast forward over half a century, and researchers tracked down 635 of the participants. 174 agreed to repeat the test, rating themselves and nominating a close friend or relative to do the same.
The researchers found there was little overlap in the questionnaire answers over the 63 years.
"Correlations suggested no significant stability of any of the six characteristics or their underlying factor, dependability, over the 63-year interval.
We hypothesized that we would find evidence of personality stability over an even longer period of 63 years, but our correlations did not support this hypothesis."
"The longer the interval between two assessments of personality, the weaker the relationship between the two tends to be
Our results suggest that, when the interval is increased to as much as 63 years, there is hardly any relationship at all."